Photographic mediums based on furfurylidenes with 1-chloro-2, 4-phenylenediamine enhancer



United States Patent PHOTOGRAPHIC MEDIUMS BASED ON FURFU- RYLIDENES WITH 1-CHLOR0-2,4-PHENYLENE- DIAMINE ENHANCER John Alan Mattor, Hollis, and Lawrence Price, Old

Orchard Beach, Maine, assignors, by mesne assignments, to Scott Paper Company, Delaware County, Pa., a corporation of Pennsylvania No Drawing. Continuation-impart of application Ser. No. 351,316, Mar. 12, 1964. This application Mar. 29, 1967, Ser. No. 626,720

4 Claims. (Cl. 96--90) ABSTRACT OF THE DISCLOSURE It has been found that in a photographic medium (film) containing a furfurylidene, a primary aromatic amine, and a lower haloalkane sensitizer, 1-chloro-2,4-phenylenediamine specifically improves the shelf life of the composition manifold over that obtained with related metaphenylenediamine enhancers.

Related application This application is a continu-ation-in-part of application Ser. No. 351,316, Photosensitive Medium Comprising a Furfurylidene, a Primary Aromatic Amine and a Lower Haloalkane, filed Mar. 12, 1964, by the present inventors and which is to be abandoned in favor of its continuationin-part Ser. N0. 641,720, filed Apr. 21, 1967.

Background of the invention The above-identified application, Ser. No. 351,316, the teachings of which are incorporated by reference, discloses a novel photographic medium comprising a resinous binder containing dispersed therein as the reactive chemicals a furfurylidene, a primary aromatic, amine and a lower halohydrocarbon light sensitizer, specifically iodoform. The medium can be imaged with ordinary actinic or ultraviolet light and after exposure is developed by heating in air to a temperature above about 100 C. This heating besides developing the image drives off the sensitizer in the background areas, and also usually the amine, so that the background is stable and no longer photosensitive.

While most of the possible combinations of the three types of chemicals give good imaging, many have been found to have limited shelf life, i.e., the photographic plates when stored prior to exposure tend to discolor or develop a background tint with time. It is believed that this may be in part due to the auto-oxidation of the primary aromatic amine enhancer.

Summary of the invention It has now been found that one of the primary aromatic amine enhancers disclosed in the above application (compound #71 therein), 1-chloro-2,4-phenylenediamine, unexpectedly imparts unusually long shelf life such that photographic plates can be stored several months without appreciable degradation. The reason why such an improvement is obtained with this specific chloro derivative and not with the related halophenylenediamines is not known with certainty but it is probably because of its unique resistance to oxidation.

The 1-chloro-2,4-phenylenediamine can be used as the sole amine enhancer in the photographic medium or in admixture with other amine enhancers. Preferably how- 3,394,393 Patented July 23, 1968 The body stock was an uncoated 28 pound per ream (3300 square feet) paper sheet that contained no fillers but was moderately sized. Sheets of the paper were impregnated with solution of the photographic medium in an amount of 4 pounds per ream (dry basis) using #16 Mayer bar, following which they were dried in air at 120 F. The sheets were translucent.

The coating solutions consisted of 600 mg. iodoform; 600 mg. difurfurylidene pentaerythritol, 1200 mg. polyphenylene oxide resin (General Electrics PPO) and various weight amounts of 1-chloro-2,4-phenylenediamine, carried as a 14 weight percent solution in chloroform. The amounts of the diamine used were 90, 180, 270, 360, and 450 mg. Similar samples were made using like amounts of meta-phenylenediamine in place of the chloro derivative.

When exposed immediately after manufacture with an ultra-violet microfilm enlarger for 20 seconds and developed by heating in air at 300 F. for 60 seconds, all samples gave good images. When stored at room temperature, the meta-phenylene diamine samples had high background color after about two weeks whereas the l-chloro- 2,4-phenylendiamine showed no major background after eleven weeks. The samples of this invention were stored 8 /2 months with refrigeration (0 F.) without the development of background.

A 28 pounds per ream paper was impregnated with 4 pounds per ream of the following:

Parts by weight Iodoform 200 Difurfurylidene pentaerythritol 200 1-chloro-2,4-meta-phenylenediamine Meta-phenylenediamine 30 Polyphenylene oxide 400 Chloroform 7170 The sheet after air drying imaged satisfactorily and had good shelf life. The meta-phenylenediamine was used in this formula to enhance the blackness of the image, although it did detract somewhat from the stability of the plate.

We claim:

1. In a photographic medium comprising a light passing resinous binder containing dispersed therein in image producing amounts and proportions a furfurylidene as a color former, a primary aromatic amine enhancer and a lower haloalkane sensitizer, the improvement wherein said amine is 1-chloro-2,4-phenylenediamine.

2. The medium of claim 1 wherein said sensitizer is iodoform.

3. The medium of claim 1 wherein said furfurylidene is difurfurylidene pentaerythritol.

4. The medium of claim 1 wherein said 1-chloro-2,4- phenylenediamine amounts to at least 50 weight percent of all primary aromatic amines present in said binder.

References Cited UNITED STATES PATENTS 3,147,117 9/1964 Wainer etal 96-90 3,202,507 8/1965 Sprague et al 96-90 NORMAN G. TORCHIN, Primary Examiner.

C. E. DAVIS, Assistant Examiner. 

